In the vector skin, How do I shrink the size of the page, similar to wikia?

Wikia has pages where the content of the page are smaller than the average computer screen, with images on both sides.

On my wikia, I have already removed the taskbar, etc. on the side, now I would like to shrink the size of the page on my wiki, so that I can add background images on both the right and left side like wikia.

I found this posting: max-width in Vector skin to control site layout width Topic:Rqxj1jgjhnr5ezt5 which changes the size of the content, but I want to have background images like wikia.

How can I do this please? Thanks in advance.

removing view history only for logged in users

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https://www.mediawiki.org/wiki/Topic:Qyydsoxnt44t8arl

Update:

What worked for me removing the view history button for non-logged in users on vector was adding this to localsettings.php:

function efAddSkinStylesAnon( OutputPage &$out, Skin &$skin ) {
      global $wgUser;
       if( !$wgUser->isLoggedIn() ) {
               // Hide history tab
               if ( $skin->getSkinName() == 'vector' ) {
                       $out->addInlineStyle( '#ca-history { display:none; }' );
               }
       }
       return true;
}

$wgHooks['BeforePageDisplay'][] = 'efAddSkinStylesAnon';

Using: MediaWiki 1.27.3

Light blue lines on side of tabs on vector

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https://www.mediawiki.org/wiki/Topic:Sbr9fajyjol1ja55